Hide Safari "Your mouse pointer is hidden" banner?

I'm trying to use the web-based architectural program [Enscape](https://en.wikipedia.org/wiki/Enscape) to view a 3D rendering. Every time I click to pan around the 3D world, Safari presents the banner: > Your mouse pointer is hidden. Press Esc (Escape) once to dismiss this banner. Press Esc again to reveal your mouse pointer. This appears to be some kind of security banner being shown by Safari in response to whatever technique the web app is using to hide the mouse cursor. Firefox on the same Mac shows a similar banner: > enscape3d.com has control of your pointer. Press Esc to take back control. The problem is that the banner pops up and down briefly every single time I click or hold down the mouse button to pan around in the CAD app. This moves the rest of the view frame down, resulting in a glitchy and jumpy visual display as I'm using the app. Like the text says, the banner hides when I press Escape and the mouse cursor is shown when I press Escape again. But the banner always comes back the next time I click so this is not a useful solution. Very annoying visual glitch that makes it almost impossible to use the web app. Is this a feature in Safari? Is there any way to turn off the notification banner permanently? (The Firefox version is also annoying, but at least pops up above the content and does not push the entire website content down.)